Method of handling strands



METHOD 6F HANDLING STRANDS Filed Aug. 14, 1941 FIGJ INVENTO R -J. N.SE1. V16

ATTORNEY Patented July 3, 1945 HANDLING s'ra Nns JdhiifN. Selvi g,Westfield, J., assigns to Western Electric Company, Incorporated, NewYork, N. Y., a corporation of New York A Application August 14, 1941,Serial No. 406,853

This invention relates to a method of handling strands, and moreparticularly to a method of making an insulatingsheath on an electricalconductor strand.

In. some instances electricalpconductor wires have of recent years cometo be insulated by forming directly on the wire a'continuous seamlesssheath of pulpous insulating material, e. g.

paper pulp fibres of cellulose-felted -or intermatted together. cellentelectrical characteristics for many uses because the sheath of feltedfibres contains a highproportion of its volume as air entrapped -Wiresthus insulated have exwithin and between its fibres; and, for 'manyuses, the higher the proportion of air thus held within the grosssurface'of .the sheath, the

greater the usefulness'of the insulation. i i. i

An object ofthe present invention is -to provide a method of making animproved sheath of pulpous material as described containing a materiallyincreased proportion of entrapped air within the grosssurface of thesheath.

With the above and other objects in view, the invention may be embodiedin a method of insulating electrical conductor strand comprising stepsof forming a ribbon or tape of wet pulpous material, applying a wire tothe partially formed tape to be enclosed therein by the complete formingthereof, compressing spaced longitudinal strips of the tape to renderthe same relatively thin,-dense and tough while leaving the corresheathas electrical wire, and folding and felting the tape into a seamlesssheathabout thewireare old and-form nopart of the present invention.Hence these are not disclosed here. Suitable procedure-and apparatus forthese purposes are disclosedand described in detail in U. S. Patent*1,61,5,;394of January 25, 1927, to J .S. Little, to which "refer encemay-be had, ifdesired, for these features. InFig. 1 hereinis showna'pair of rolls l0 and II to receive. a plurality of flat ribbons ortapes 2!] of wet paper pulp each having a metal wire 2| embedded andcontained within it. Thelower roll I0 is provided with a surface ofhard:material, metal, hard rubberyhard fibre; artificial resinor othersuitable substance, and is formed with parallel peripheral grooves 12and 13 of two kinds distributed in repeated duplications of one set orpattern I l for each wire bearingta pe 20;

For clarity, only one tape is shown, but in practise there will usuallybe a plurality of tapes, The middle groove 13 of each set or pattern 14of groovesis deeperand widerthananyother groove of the set and receivesand gives passage to that part of the tape 20 which contains the wire2|. Oneither side of the groove [3 isa plurality of parallel grooves I!all preferably alike and equally spaced apart. The roll II is smooth onits surface and is made to have its "outer surface relatively soft andelastically yieldsponding intercalated strips, thick and fluffy, and

the material into a seamless sheath.

Other objects and features of the invention will appear from thefollowing detailed descrip tion of one embodiment thereof taken inconnection with the accompanying drawing in which the same referencenumerals are applied to identical par-ts in the several figures and inwhich Fig. 1 is a broken diagrammatic view. in eleva tion of a pair ofrollers for squeezing a tape of wet paper pulp having a wire embeddedtherein;

Fig. 2 is aplan view of a portion of such tape after squeezing;

Fig. 3 is a section on the line 3-3 of Fig. 2; and i Fig, 4 is a viewsimilar to Fig; 3 showing the tape formed into a cylindrical sheathabout the wire. i The general procedure and apparatus for creating atape of wet pulpous material such as paper pulp, applying a wire to thepartially formed tape, completingthe tape to contain the ing, e. g. bymaking the body of the roll through-. out of suitablematerial or byproviding a hard] cored. roll with a surface layer or sheath l5 of j isuitable material, e. g. soft vulcanized rubber,

vulcanized corn oil, or the like.

the wire 2|, strongly compressed by the roll ll where the tape lies onthe lands l6 while [the portions betweenthese compressed parts aremerely pressed down into the grooves I2 by the roll ll without anymaterial compression of the substance of the tape in these portions.Hence the tape emerges from the rolls I!) and H sub-x stantially in thestate disclosed in Figs. 2 and 3.

The longitudinal strip portions H6 which were pressed by the lands l6 ofthe roll l0 are thin, dense and tough while the intercalatedlongitudinal strip portions 2 or the tape which were a kept free ofpressure by the grooves [20f the A tapezu with its wire 2! in passingover the roll ID, has its lateral portions at each side of i of thestructure so made, is the presence in the sheath 220 of longitudinallyextending passages 222 created by the wrapping of the longitudinallyridged tape I20; It is the presence of these longitudinal voids,passages or ducts 222 within the body of the sheath 220 in the finishedproduct that notably increases the value of the sheath as an insulator.Another feature of importance is the presence within the sheath of thelongitudinally extending, thin, hard pressed, tough strips 2l6corresponding to the elements H6 in Figs. 2 and 3. Paper pulp and fluffypaper at best have no great tensile strength, and when the sheathed wireis subjected to more or less severe bending or pulling or friction insubsequent manipulation or use there may be danger of rupture of thesheath, especially transversely of the wire. In the wire shown in Fig. 4the longitudinal strips 216 integrally parts of the sheath havea-tensile strength which may be several times that of any partof asheath of undifferentiated structure, and so tend to support and savethe sheath 220 as a whole where an ordinary pulp sheath might well beruptured.

. The embodiment of the invention herein disclosed is illustrative andmay be variously modified and .departed from without departing from thespirit and scope of the invention as pointed out in and limited only bythe appended claims.

What is claimed is:

. 1. Ina method of insulating an electrical conductor and which methodincludes a step of creating a tape of pulpous material containing awiretherein anda step of wrappingthe tape about the Wire to form asubstantially seamless sheath about the wire, a step following the stepof creating the tape and preceding the step of aplurality of mutuallylaterally spaced longitudinal portions of the tape to create in the tapelongitudinal strips which are thin, dense and tough intercalated withstrips which are thick and fluffy.

2. In a method of insulating an electrical conductor and which methodincludes a step of 4 creating a continuously advancing tape of pulpousmaterial containing a wire therein and a step of wrapping the tapeaboutthe wire to form a substantially seamless sheath about the wire, a stepfollowing the step of creating the tape and preceding the step ofwrapping the tape which step consists in supporting a transverse portiononly of the advancing tape on one side thereof, and a step simultaneoustherewith of exerting pressure at a fixedlocation on a transverseportion only of the advancing tape on the other side thereof and onlyover a plurality of mutually laterally spaced longitudinal portions ofthe tape to create in the tape longitudinal strips which are thin, denseand tough intercalated withstrips which are thick and 3. Ina method ofinsulating an electrical conductor and which method includes a step ercreating a continuouslyadvancing tape of pulpous material containing awire therein and a step .of wrapping the tape about the wire to form asubstantially seamless sheath aboutthe wire, astep following the step ofcreating the tape and preceding the step of Wrapping the tape which stepconsists in supporting a transverse portion only of the advancing tapeon one side thereof on a roller, and a step simultaneous therewith ofexerting rolling pressure on the transverse portion of the tape'onxtheroller thereof and only oyer a plurality of mutually laterally spacedlongitudinal portions of the tape. to create in the tape longitudinalstrips which are thin, dense and tough intercalated with strips whichare thick and flufiy.

JOHN N. SELVIG.

